1. Technical Field
The present invention relates to configuring and managing storage devices in a computing system to improve operational availability of the computing system. More particularly, the invention concerns a method and apparatus for managing storage devices, that provides data mirroring, and that also permits updating code while continuing to operate the computing system with at least one of the storage devices.
2. Description of Related Art
It is desirable for computing systems to have maximum operational availability and as little downtime as possible. Problems related to disk drives can result in system down time. For example, down time can result from disk drive hardware failures, and errors caused by code updates.
Using a single disk drive can result in significant downtime if the disk drive has a hardware failure. Downtime resulting from hardware failures can be reduced by using two disk drives, with the computing system configured to redundantly store information on both of the drives. This configuration, which is referred to as mirroring across the drives, reduces problems related to single disk drive failures, because if one of the drives fails the system can continue to operate with the other drive.
It is frequently desirable to update computer code, for example operating system code, on disk drives. If code updates are implemented on drives that are operated in a mirrored configuration, any problems caused by the updated code will affect both drives, and will likely result in system downtime.
Consequently, existing configurations for operating disk drives in computing systems are not completely adequate for minimizing downtime related to hardware failures and code update errors.